Pressurized CEC coupled with QTOF-MS for urinary metabolomics

Area of Science:

• Analytical Chemistry
• Metabolomics
• Biochemistry

Background:

• Metabolic profiling of biofluids like urine is crucial for disease biomarker discovery.
• Existing analytical methods may face challenges in separating and identifying complex metabolite mixtures.

Purpose of the Study:

• To develop and validate an alternative analytical method for urine metabolomics using pressurized capillary electrophoresis coupled with electrospray ionization-quadrupole time-of-flight mass spectrometry (pCEC-ESI-QTOF-MS).
• To assess the performance of the pCEC-ESI-QTOF-MS system for precision, repeatability, linearity, sensitivity, and selectivity.
• To apply the optimized method for distinguishing lung cancer patients from healthy controls based on urinary metabolite profiles.

Main Methods:

• Development of a sheathless interface for pCEC coupled with ESI-QTOF-MS.
• Optimization of applied voltage, mobile phase, and gradient elution for urinary metabolite analysis.
• Application of multivariate data analysis for distinguishing patient groups.
• Identification of differential urinary metabolites using pCEC-MS separation mechanisms and fragmentation patterns.

Main Results:

• The pCEC-ESI-QTOF-MS system demonstrated high separation efficiency.
• Multivariate analysis successfully differentiated lung cancer patients from healthy controls.
• Three glutamine conjugates (phenylacetylglutamine, acylglutamine C8:1, acylglutamine C6:1) were identified among 16 differential metabolites.
• Acylglutamine C8:1 showed an area-under-the-curve of 0.882 in receiver-operating-characteristic analysis.

Conclusions:

• The developed pCEC-ESI-QTOF-MS method offers superior separation and identification capabilities for metabolomic studies.
• This technique provides a novel and useful platform for metabolic profiling of complex biofluids.
• The identified glutamine conjugates show potential as biomarkers for lung cancer detection.